Casting methods currently used to produce items of metal alloys employ molding techniques that replicate the interior and exterior features of a desired part. Such methods comprise an exterior mold that replicates the external surface features of the desired part, while a core or cores are used to replicate interior cavities and surfaces if such parts embody hollow or reentrant features. The mold and cores are produced from a pattern of the part and are assembled together to produce a cavity that replicates the volume and surface features of the desired part. Cores are subsequently placed within the mold and the mold halves fitted together to form a core mold assembly. A system of sprues, runners, gates and risers embodied within the core mold assembly provide the requisite channels to direct molten metal poured into the formed part cavity to reproduce the part. Molten metal is poured into the core mold assembly and is allowed to cool and solidify. Once the casting has cooled sufficiently, the cast part is shaken from the sand mold and the cores removed leaving the desired replicated part. The mold and core sand are usually reclaimed and reused.
Of the various types of molding methods used, molds made from “green sand” are the most widely used. Green sand is made from a pliable mixture of sand, clay, and water that coheres and can be molded in such a fashion as to faithfully replicate surface features of the part pattern shape. However, significant disadvantages are associated with the green sand method, some of which are the need for careful handling of the core mold assembly due to the relative fragility of the green sand, as well as undesirable dimensional variations between castings associated with mold cavity, core misalignment and pattern wear. Additionally, green sand molding techniques typically employ core sand compositions that differ from molding sand making reclamation of these components difficult in that they are mixed during the part removal process and thus can cross-contaminate each other. Furthermore, multiple parts are typically cast at one time by using a plurality of part patterns to form several mold cavities within a single flask (i.e., frame) using a system of common runners. Such an arrangement increases the number of parts that may need to be scrapped due to core mold assembly misalignments and cold-shunting. What is needed is an improved casting apparatus and method to overcome these and other drawbacks.